The transistors in semiconductor chip continue to shrink in order to reduce costs, size, and power consumption. As the devices on a chip become smaller, the voltage used to drive the transistors also becomes smaller. While chips from a few years ago operated on 3 to 5 Volts, newer chips operate on 1 Volts or less. This not only reduces the overall power required for the chip but also reduces the amount of power that is lost or wasted by the chip and is converted to heat. Reducing the amount of heat produced by the chip allows the chip's package to be smaller. It also allows the heat fins and air circulation for the chip to be reduced.
In another direction, more circuits are being added to each chip in order to reduce the total number of chips required to build a system. This reduces the size, complexity, and power consumption of the system that houses the chips. With an SOC (System on a Chip), designers strive to put all of the circuitry for a complete system on one chip and in one package. The SOC objective has been reached for some simple devices. For more complex devices there are difficulties putting all of the components on the same type of chip. With an SiP (System in a Package), designers strive to put all of the circuitry for a system in one package. The package contains more than one chip so that different types of circuits may be made using different types of chips. While the chips for an SiP are easier to design and package, it is generally more expensive to make multiple chips than it is to make one chip. It is also more expensive to package several chips together than to package a single chip.
For a true SOC, the chip must include logic and memory circuitry together with power circuitry. For some systems, the chip must also include analog audio amplifiers, baseband radio circuitry, and possibly radio frequency multiplexers, amplifiers and other higher power devices. Low power CMOS (Complementary Metal Oxide Semiconductor) technology is well established for low power logic and memory. The higher power circuits may be made by modifying standard CMOS devices. As examples, there are extended drain devices and lateral drifted channel devices.